The proposed research will explore the influence of nutritional status on endocrine responses to a meal beginning with endocrine responses to a meal in a state of starvation, as seen in subjects with anorexia nervosa (AN). It is well established that starvation alters levels of circulating hormones that influence food intake, such as leptin, insulin, ghrelin, and cholecystokinin. However, controlled studies measuring responses to a test meal have not been conducted. Additionally, within the Eating Disorders Program at Johns Hopkins Hospital, the source of our AN subjects, patients are subjected to a period of rapid weight gain. This is a unique physiological situation for which endocrine responses to meals have not been measured. Within this study, we will assess endocrine and subjective responses (hunger, satiety, nausea, anxiety) in human subjects with AN and compare them not only to healthy controls, but also to within subject responses during the process of rapid refeeding and when weight is restored to normal. We will also use a' rodent model of starvation and rapid refeeding to examine changes in peripheral levels of a number of feeding-related peptides and central levels of gene expression NPY, POMC, AgRP, and CRF.